Six Year-End Moves Worth Considering Before December 31

Fourth quarter is when a projection earns its keep. If you know roughly where taxable income will land, several decisions become straightforward. If you don't, you're guessing with real money.

1. Accelerate or defer income

For cash-basis businesses, when you invoice and when you collect are partly within your control. If next year looks materially lighter, pulling income forward can be wrong; if it looks heavier, deferring can be wrong. The projection decides.

2. Fund the retirement plan properly

Plan type matters more than contribution timing. A solo 401(k), SEP, or defined benefit plan each has a different ceiling and a different setup deadline. Some must exist before year end even if funding comes later.

3. Time equipment and vehicle purchases

Placed-in-service date, not purchase date, controls the deduction. A truck delivered January 3 does nothing for the year that just closed.

4. Clean up the accountable plan

Home office, mileage, and travel reimbursements are legitimate and often under-claimed — but they need a written plan and contemporaneous records, not a December reconstruction.

5. Review owner compensation

If the S corp salary is off for the year, Q4 payroll is the last chance to correct it cleanly.

6. Confirm estimated payments

Underpayment penalties are avoidable and entirely unnecessary. A December true-up costs far less than the penalty and the March surprise.